I’m a card-carrying member (so to speak) of BAARF, a little online group dedicated to dispelling the myth that RAID5, or any variant thereof, is a good compromise for capacity and fault tolerance. The reason I bring this up is that I had two hard drives fail earlier today (on separate machines), of which one was RAID5 (it’s not mine). The RAID5 box is still rebuilding, one hard drive failure away from data oblivion. Please, for the love of all that is sacred in storage, don’t trust your data to RAID5, or even RAID6, which is not a whole lot better.

Also, it makes me sad that someone would dedicate some very nice 15K RPM SAS drives to a RAID5 array, presumably to offset the characteristically low IOPS performance of any RAID3/4/5 variant. Listen folks: you can have good IOPS as well as high capacity with other RAID levels, namely RAID10, which offers the best compromise of both worlds. I won’t go into too many details here, the page linked below has a number of good reference write-ups, but the gist is that dedicating resources to parity management (the calculating, reading, and writing of parity data) is a practice that sucks and deserves a swift boot into tech obscurity along with floppy drives and modems.

You may join the fight, or not. Either way, enough is enough.